1. Field of the Invention
The present invention relates to a sheet material having the same touch and drape characteristics as a natural suede and a method of producing the same.
2. Description of the Prior Art
Many synthetic suede-like sheet materials have already been suggested and a number of these materials are commercially available.
Generally speaking, the synthetic suedes or the process for prdducing these materials can be classified into the following five catefories: (1) a product made by buffing a fabric made of fibers of about 1 denier; (2) a product made by impregnating a nonwoven fabric made of fibers of more than 1 denier with an elastomer such as polyurethane and then buffing the product; (3) a product made by buffing a woven fabric formed from a composite of fibers or blended polymer fibers made of two or more incompatible polymers, wherein these fibers are used for the weft yarn in order to divide the weft yarn into ultrafine fibers of the individual polymer; (4) a product formed by impregnating a nonwoven fabric prepared from the composite fibers or polymer blended fibers of (3) above with an elastomer and then dissolving and removing one component of the composite fiber or blended polymer fibers thereby rendering the fibers very fine; and (5) a product made by mechanically or chemically treating a nonwoven fabric impregnated with the elastomer of part (4) above to divide the composite fibers or blended polymer fibers into individual polymer components thereby finely dividing the fibers. Among these classifications, the products formed from very fine or ultrafine fibers as described in parts (3) to (5), are closest in appearance, touch and hand to natural suedes. In all of these products, the very fine or ultrafine fiber bundle is considered as one unit. For example, sheets of products of classifications (4) and (5) are of a structure based upon ultrafine fiber bundles which are present in large amounts within the elastic polymer. As a result, when such products are buffed, a suede-like product is obtained. However, because the sheet characteristics are determined principally by the structure and character of the elastic polymer layer which is present in the sheet in large amounts, the products will be of a touch and drape substantially different than those of a natural suede. Therefore, a need continues to exist for a synthetic material which exhibits more suede-like characteristics.